Abstract: Impact of channel estimation error on the throughput of zero-forcing beam forming (ZFBF) is studied in this paper.By computer simulation, relations between the incurred throughput loss due to channel estimation error and the system parameters such as number of users, SNR, number of transmitting antennas and the order of data sub-stream are investigated.Simulation results demonstrate that, when the user number is moderate, a ZFBF system demonstrates its advantage over random beamforming (RBF) in terms of the linear increase of throughput with the number of transmitting antennas even under imperfect channel estimation at the transmitter.Also, in this paper, a referenced rate factor is given to meet the specific outage requirement of system.The results provide a reference for the design of practical downlink multi-antenna multi-user systems.

Key words: channel estimation error, zero-forcing beamforming, downlink multi-antenna multi-user system, throughput analysis